Recent research suggests a reversal in the trend evident between 1922 and 1966 of consistently lower arrest rates for former mental patients as compared to the general population. These recent studies question the advisability of current trends toward de-institutionalization. However, none of these studies have compared the rates of arrest of former mental patients with ex-offenders. Such comparisons have considerable policy important in the area of social control since mental patients may be detained indefinitely in hospitals because of a probability for future violence towards others, while offenders, after completing a designated sentence, may be released without an evaluation of their likelihood for future violent behavior. This study compares the arrest rates of ex-mental patients, ex-offenders, and the general population in an urban, upstate New York jurisdiction. Criminal and hospitalization data have been compiled on 511 mental patients and 419 offenders released to the community in either 1968 or 1975. Subsequent arrest rates of these two groups will be compared. These data will be used to draw implications concerning the appropriateness of policies for social control of mental patients and offenders. In addition, the project will demarcate conceptually and empirically sound comparison groups that will be used to study the role of situational factors in violent behavior.